This invention relates to an adhesive patch for use on humans or animals which is adhered to a patient's skin allowing a health care practitioner to puncture the patient's skin while minimizing the risk of contact with the patient's blood.
It is widely recognized that blood-borne pathogens are an important and serious method of transmission of infectious diseases. Health care practitioners, in particular, are in danger from such exposure because of the need to perform functions that directly expose the practitioner to blood, such as puncturing a patient's skin with a needle to make an injection or to withdraw blood. Typically, when the skin is to be punctured, the target area of the skin is wiped with a disinfectant and the needle (which may be further attached to a syringe) is injected through the skin subcutaneously or intramuscularly. After the skin has been punctured, the needle is withdrawn and a pad of gauze or cotton is placed on the puncture wound to absorb any blood which may emanate therefrom. The practitioner may come into contact with the blood at several points during this procedure, such as when the needle first punctures the skin, when the needle is removed from the skin but before the pad is positioned over the puncture wound, or after the pad is applied over the puncture site because blood may ooze from or seep through the pad.
Attempts have been made to provide a protective patch that is applied to the skin prior to the skin being punctured. For example, U.S. Pat. Nos. 5,728,071 and 5,738,641, both issued to the present applicant and incorporated herein in their entirety by reference, describe patches that adhere to the patient's skin and minimize the risk of blood contact during injections and blood withdrawal procedures, respectively. The '071 patch is a three layer system comprising a generally annular absorbent pad having a first surface to be placed against the skin of a patient around an intended injection site, a second surface opposite said first surface and a central opening; an elastomeric, self-sealing membrane through which an injection needle can penetrate, said membrane lying against said second surface and closing said central opening, said membrane, in use, being spaced from the patient's skin and forming a cavity between said membrane and said skin surrounded by said absorbent pad; and a cover layer having a central opening substantially aligned with said central opening of said pad and exposing a central portion of said membrane to identify the injection site. The '641 patch is a three layer system comprising an absorbent pad having a first surface to be placed against the skin of a patient around an intended penetration site for injection or withdrawal and a central opening; a transparent, elastomeric, self-sealing membrane through which a needle can penetrate; and a transparent cover layer having an outer surface and an adhesive surface for holding said membrane in said central opening of said pad and for adhering said patch to skin of a patient, and having a central opening substantially aligned with the central opening of said pad to expose a central portion of the membrane allowing visual identification of a selected penetration site whereby a blood vessel can be located through the membrane and cover and a needle can be passed through said membrane and the patient's skin into a vessel for injection or blood withdrawal, and whereby, after injection or withdrawal, the needle is extracted, the membrane wipes the needle and forms a cavity with the pad and the patient's skin to contain blood from the penetration site until after hemostasis. While these patches have been effective for restricting the free flow of blood when the skin is punctured, they are difficult to manufacture because of the need to carefully align the openings in the various layers. Further, the top surface layer of these patches is susceptible to degradation when wiped with an antiseptic. Therefore, each patch must be individually wrapped and sterilized and then carefully maintained sterile by the clinician while using since wiping with alcohol to maintain sterility may degrade the pad. Finally, neither patch provides a means for the blood to coagulate so a nominal risk remains that a practitioner could be exposed to blood oozing from the absorbent pad upon removing the patch from the patient.
Thus, it would be beneficial to have a protective patch for use during injections and blood withdrawal procedures that does not require complex registering of the layers, that is relatively easy and inexpensive to manufacture, that has a top surface that can be wiped with an antiseptic such as alcohol while using, and that may include a means for coagulating blood collected within the patch, thereby essentially eliminating the risk of unintended blood contact.